Voriconazole

Restricted
Restricted

C. diff Risk

Low

Oral Bioavailability

Excellent

Approximate Cost

Dosing

Requires Infectious Disease consultation for use OR completion of the Restricted Antimicrobial order form for approved indications IV: 6 mg/kg IV every 12 hr x 2 doses then 4 mg/kg IV every 12 hr PO: 400 mg PO evey 12 hr x 2 doses then 200 mg PO every 12 hr Dose reduction may be required if low body weight (< 40 kg)

Severe impairment (Child-Pugh C)
Should only be used if benefit outweighs risk

Mild to moderate (Child-Pugh A/B)
Standard loading dose then reduce maintenance by 50%

General Information

Acceptable Uses

Broad-spectrum antifungal therapy needed and one of the follwoing criteria met:

  • SCr >2.5 or doubled from baseline

  • Patient receiving tacrolimus, cyclosporine, aminoglycoside, or cyclophosphamide

  • BMT or solid organ transplant patient

Unacceptable Uses

  • Candidiasis/Neutropenic fever: Voriconazole should not be used as first-line therapy for the treatment of candidiasis or for emperic therapy in patients with neutropenic fever

Common Usage

Candida infections both mucocutaneous and invasive - i.e. Candidemia.

Antifungal prophylaxis in immunocompromised patients.

Drug Monitoring

Lab

  • Therapeutic drug monitoring may be helpful to ensure adequate concentrations and exclude toxicity (Discuss with ID).

  • Baseline LFTs and weekly for the first month

  • Serum trough levels at steady state (5-7 days). Target 2-5 mcg/ml

Clinical

  • QTc interval in patients at elevated risk

  • Hypersensitivity

  • GI effects

  • visual disturbances

Adverse Effects

  • Drug interactions

  • QTc prolongation

  • Hepatic enzyme abnormalities

  • Rash - up to 20%

  • Visual disturbance

  • Fluorosis

  • ¬†GI upset

Major Interactions

CYP450 interactions ++.

Other QTc prolonging agents.

Recommend review of pt medications due to high frequency of significant interactions.

Pharmacology

Antimicrobial class: Triazole antifungal, Second generation

Pregnancy category: D

Lung penetration: Therapeutic

CSF penetration: Therapeutic

Urine penetration: Poor